Boiler Upgrade Scheme Air Source Heat Pump Grant 2026

For most homeowners replacing a mains-gas boiler with air-to-water, £7,500 is the relevant figure.

The £9,000 rate is not a general rural-home bonus. It applies where the property has no mains gas connection and the existing heating system uses oil or LPG. The £9,000 rate took effect on 21 July 2026.

You can get one BUS grant per property. The installer applies for the voucher and deducts the grant from the amount you pay.

Visual suggestion: Simple three-way graphic comparing the £7,500 air-to-water grant, £9,000 off-gas uplift and £2,500 air-to-air grant.

Am I Eligible for the Boiler Upgrade Scheme Air Source Heat Pump Grant?

You are likely to meet the basic criteria if:

1. You own the property, including a main home, second home, privately rented property or eligible business property.
2. The property is in England or Wales.
3. You are replacing an existing fossil-fuel or electric heating system.
4. The proposed heat pump meets BUS technical standards.
5. An MCS-certified installer carries out the work and manages the application.
6. You have not already received prohibited public funding towards the purchase or installation of the same heat pump.

Current GOV.UK guidance confirms that property ownership can include a home, business property, second home or property rented to tenants. Ofgem separately confirms that an eligible new system can replace either fossil-fuel or electric heating. Read the official BUS eligibility rules on GOV.UK

Do I Need an EPC for the Boiler Upgrade Scheme?

A valid Energy Performance Certificate is no longer a standing BUS eligibility requirement for applications properly made from 28 April 2026.

If a valid EPC exists, it can still help verify property information. Where one does not exist, alternative evidence may be required.

This change is particularly important when researching BUS online because many older guides still describe an EPC as compulsory. See Ofgem’s current Boiler Upgrade Scheme property-owner guidance

Visual suggestion: Yes/no BUS eligibility flowchart covering ownership, location, existing heating, technology and MCS requirements.

Which Properties or Systems Do Not Qualify?

You normally cannot use BUS to replace an existing low-carbon heating system, such as another heat pump.

Most developer-built new homes are also excluded. However, qualifying self-build properties can be eligible.

Social housing is outside BUS. The scheme also cannot normally be combined with another government or Energy Company Obligation grant that pays towards the purchase or installation of the same heat pump. Separate funding previously used for measures such as insulation does not necessarily prevent a BUS application.

Hybrid systems are another important exclusion. A new heat pump designed to operate as part of a fossil-fuel hybrid system, such as alongside a gas boiler, is not eligible.

The installation must meet technical rules too. Ofgem states that air-to-water heat pumps need a minimum seasonal coefficient of performance, or SCOP, of 2.8. Individual systems are generally capped at 45kWth, which covers most domestic properties.

Does the Heat Pump Have to Replace My Boiler Completely?

For an air-to-water BUS installation, the heat pump must be sized to meet the property’s full space-heating requirement and comply with the scheme’s hot-water and supplementary-heating rules.

BUS is therefore not intended to subsidise a heat pump that simply assists a gas or oil boiler while fossil-fuel heating remains part of the new hybrid system.

This does not mean every radiator needs replacing. Some existing radiators may provide enough heat at the proposed operating temperature.

If you are deciding whether to remove gas heating altogether, see our detailed air source heat pump vs gas boiler comparison.

How Does an Air-to-Water Heat Pump Work?

An air-to-water heat pump extracts low-temperature heat from outdoor air through a refrigeration cycle.

Outside air passes across the evaporator, where refrigerant absorbs heat. The compressor raises the refrigerant’s pressure and temperature.

At the condenser, that heat transfers into water for radiators, underfloor heating and usually a hot-water cylinder. An expansion valve then lowers the refrigerant pressure so the cycle can repeat.

This process explains why the technology can still extract useful heat when outdoor temperatures are low. Winter conditions can reduce efficiency, and frost on the outdoor coil may trigger an automatic defrost cycle.

For a fuller explanation of the evaporator, refrigerant, compressor, condenser and expansion valve, read how air source heat pumps work.

Visual suggestion: Labelled refrigeration-cycle diagram showing the evaporator, compressor, condenser, expansion valve, radiators and hot-water cylinder.

Is My Home Suitable for a BUS-Funded Air Source Heat Pump?

Grant eligibility does not automatically mean a proposed system is a good fit for your property.

A proper assessment should establish:

• room-by-room heat loss;
• required heat-pump output;
• proposed heating-water flow temperature;
• radiator or underfloor-heating capacity;
• household hot-water demand;
• hot-water cylinder space;
• outdoor-unit positioning.

Heat pumps usually work most efficiently at lower heating-water temperatures than traditional boilers.

Air source heat pumps also operate during cold weather, although efficiency generally falls as outdoor temperatures drop. The useful question is whether the proposed unit can still meet your home’s calculated winter heat loss.

How Much Might I Pay After the BUS Grant?

Energy Saving Trust currently gives around £12,000 as a typical air source heat pump installation cost. Your actual quotation can be higher or lower depending on the property and required work. See Energy Saving Trust’s current air source heat pump guidance